Oxidation of (c5H5)3U111.THF with oxygen in tetrahydrofuran yields the linear bridge complex [(C5H5)3u-O]. Three cyclopentadienyl rings are n5-covalently bonded to each uranium atom to form a distorted tetrahedron with one bridging oxygen atom. The U-O-U angle is 180* with the oxygen atom on a centre of inversion. The U-O distance, 2.0881(4) A, is among the shortest ever observed. The temperature-dependent paramagnetic susceptibility of the compound was measured in the temperature range between 4.2 and 300 K and is discussed in comparison with the magnetic susceptibilities of (C5H5)3UOH, (C5H5)3USH and [(C5H5)3U]2[n-S].